Post by PVP on Feb 9, 2010 12:50:38 GMT -5
Blossom End Rot (BER) often plagues tomato growers. It's thought to be caused by the interupted or insufficient delivery of calcium to developing walls of the young, green fruit.
BER appears on the blossom end of the still green fruit as a blotch of black or brown, leathery, sunken skin. The rot extends into the fruit and renders it largely unusable. The fruit should be removed and discarded because the rot continues to degrade the fruit and provide fungi and bacteria a route into the tomato plant.
There are several ready-made products and home remedies promoted as spray-on cures or drenches for BER. But nothing beats good cultural practices to prevent or avoid BER rather than running to the store when you see it appear on your first few tomatoes of the year. Besides, by employing good garden practices, you usually are rewarded by healthy plants outgrowing their tendency toward the initial outbreak of BER.
The following is my attempt to address a few issues that I believe will help the home gardener avert or minimize BER:
First of all, these storebought BER products are basically expensive solutions of calcium peddled, in my opinion, to amateurs or old men with too much spare change rattling around in their pockets.
Besides, the only time calcium can penetrate the green fruit walls is early in the development of the little fruit while they appear "fuzzy" or feel tacky which indicates their skins are still permeable. After than, the little green tomatoes develop a shiny, waxy skin that sheds the water based solution.
I'm not going to address the effectiveness of foliar applications of calcium and subsequent theoretic delivery to the fruit walls, because I don't know anything about it. Someone else may wish to address that issue.
So basically, I think good cultural practices are preferred and more effective than spraying calcium solutions on your tomato plants or otherwise topically applying the calcium to the outside of the tomato fruit.
For tomatoes, I believe you should keep the soil pH at 5.8 or 6.5 which is a bit on the acid side of 7.0 neutral pH. To do this, perform a soil test to determine the pH of your tomato bed.
If a base mineral is needed to raise the alkalinity of soil up to 5.8 to 6.5, apply the recommended rate of lime using dolomitic or high-calcium natural limestone. Be sure to apply lime two to four months before planting tomatoes to give the calcium time to marry into the soil. Typically, autumn is the best time to adjust garden soil pH.
If an acid mineral is needed to lower the pH of your soil, use sulfur.
Also before planting, apply the required (recommended for tomatoes) amount of fertilizer, when necessary, based on soil test results. Healthy tomato plants are less likely to suffer BER and healthy tomato plants depend on the correct balance of nutrients and ample supply of micronutrients. But applying too much fertilizer at one time can induce BER, especially too much nitrogen.
While it may sound contradictory, a follow-up side dressing of fertilizer formulated for tomatoes, and containing some nitrogen, may be needed at first fruit set for semi-determinates and heavier producing indeterminates that you wish to extend plant health into the late summer and fall. For this side dressing application, I prefer something like a cheap Dollar General or Walmart 9-12-12 or 10-15-15 granular.
Remember, you paid for the soil test, so you may as well use the resulting recommendations. By following soil test recommendations you ensure proper soil fertility.
Mulch heavy with high organic content mulch to conserve moisture and help bind up nutrients for healthy root growth and maximize their ability to take in and deliver calcium and other nutrients from the soil. Good mulching practices will dramatically reduce incidence of BER.
Some tomato varieties tend to be more sensitive to conditions that cause BER. Some varieties are known to be overly susceptible to BER while some varieties are known to be resistant. If you are growing heirlooms or paste tomatoes, try growing several varieties and keep notes regarding incidents of BER, etc.
Depending on "mono-culture" (growing one variety for one purpose) with tomatoes is a sure route to disappointment for the hobby gardener or home canner. Mix it up a bit.
Keep plants adequately irrigated. Tomato plants need the equivelent of 1.5 inches rainfall weekly during the flowering and fruiting cycle. Too dry soil can exacerbate BER and chronic wetness can drown roots, shut them down and cause BER. Also, radical fluctuations in soil moisture can result in a greater incidence of BER ... like letting your containers or beds go dry and then soaking them down. Even watering is the key. Soaker hoses or drip lines are great if you can afford them. I use heavily organic soil topped with heavy mulch because I'm cheap.
Be very careful not to roto-till, hoe or otherwise cultivate the soil within the major root zone of a tomato plant. Root pruning during fruit development will cause BER. Again, mulch heavy and maybe lay down walking path boards to protect against soil compaction or root damage especially when your rows are close together and the root zone extends into the space between the plant rows.
If you still end up experimenting with or applying a calcium solution directly to the plants ... whether foliar sprays, topical applications to the fruit, or root drenches ... try a calcium solution at the rate of 4 tablespoons (level, not heaping) calcium chloride or calcium nitrate per one gallon of water.
Always be careful with calcium chloride because at daytime temperatures above 85* F, calcium chloride can burn tomato plants. If you have to spray calcium during high temp. conditions, calcium nitrate is a better choice.
Problem, again, with spraying calcium, you need to spray two or three times a week beginning when the second flower blossoms begin blooming, assuming you're getting fruit set, to do any good delivering the calcium to its target destination inside the developing young fruit walls. And such frequent applications, especially if they are root drenches, may risk altering soil pH. But you can test for that at the end of the season and, if needed, add sulfur to rebalance your soil toward acidity.
Remember, spraying calcium will not substitute for proper cultural practices such as cultivar selection, soil building with organic material, soil fertility management, soil pH management, mulching, and proper irrigation.
Also remember, if you get BER, immediately remove and discard the damaged fruit because the rot will continue to degrade the tomato and provide bacteria and fungi a route into the plant.
Good growing in 2010!!!
Bill
BER appears on the blossom end of the still green fruit as a blotch of black or brown, leathery, sunken skin. The rot extends into the fruit and renders it largely unusable. The fruit should be removed and discarded because the rot continues to degrade the fruit and provide fungi and bacteria a route into the tomato plant.
There are several ready-made products and home remedies promoted as spray-on cures or drenches for BER. But nothing beats good cultural practices to prevent or avoid BER rather than running to the store when you see it appear on your first few tomatoes of the year. Besides, by employing good garden practices, you usually are rewarded by healthy plants outgrowing their tendency toward the initial outbreak of BER.
The following is my attempt to address a few issues that I believe will help the home gardener avert or minimize BER:
First of all, these storebought BER products are basically expensive solutions of calcium peddled, in my opinion, to amateurs or old men with too much spare change rattling around in their pockets.
Besides, the only time calcium can penetrate the green fruit walls is early in the development of the little fruit while they appear "fuzzy" or feel tacky which indicates their skins are still permeable. After than, the little green tomatoes develop a shiny, waxy skin that sheds the water based solution.
I'm not going to address the effectiveness of foliar applications of calcium and subsequent theoretic delivery to the fruit walls, because I don't know anything about it. Someone else may wish to address that issue.
So basically, I think good cultural practices are preferred and more effective than spraying calcium solutions on your tomato plants or otherwise topically applying the calcium to the outside of the tomato fruit.
For tomatoes, I believe you should keep the soil pH at 5.8 or 6.5 which is a bit on the acid side of 7.0 neutral pH. To do this, perform a soil test to determine the pH of your tomato bed.
If a base mineral is needed to raise the alkalinity of soil up to 5.8 to 6.5, apply the recommended rate of lime using dolomitic or high-calcium natural limestone. Be sure to apply lime two to four months before planting tomatoes to give the calcium time to marry into the soil. Typically, autumn is the best time to adjust garden soil pH.
If an acid mineral is needed to lower the pH of your soil, use sulfur.
Also before planting, apply the required (recommended for tomatoes) amount of fertilizer, when necessary, based on soil test results. Healthy tomato plants are less likely to suffer BER and healthy tomato plants depend on the correct balance of nutrients and ample supply of micronutrients. But applying too much fertilizer at one time can induce BER, especially too much nitrogen.
While it may sound contradictory, a follow-up side dressing of fertilizer formulated for tomatoes, and containing some nitrogen, may be needed at first fruit set for semi-determinates and heavier producing indeterminates that you wish to extend plant health into the late summer and fall. For this side dressing application, I prefer something like a cheap Dollar General or Walmart 9-12-12 or 10-15-15 granular.
Remember, you paid for the soil test, so you may as well use the resulting recommendations. By following soil test recommendations you ensure proper soil fertility.
Mulch heavy with high organic content mulch to conserve moisture and help bind up nutrients for healthy root growth and maximize their ability to take in and deliver calcium and other nutrients from the soil. Good mulching practices will dramatically reduce incidence of BER.
Some tomato varieties tend to be more sensitive to conditions that cause BER. Some varieties are known to be overly susceptible to BER while some varieties are known to be resistant. If you are growing heirlooms or paste tomatoes, try growing several varieties and keep notes regarding incidents of BER, etc.
Depending on "mono-culture" (growing one variety for one purpose) with tomatoes is a sure route to disappointment for the hobby gardener or home canner. Mix it up a bit.
Keep plants adequately irrigated. Tomato plants need the equivelent of 1.5 inches rainfall weekly during the flowering and fruiting cycle. Too dry soil can exacerbate BER and chronic wetness can drown roots, shut them down and cause BER. Also, radical fluctuations in soil moisture can result in a greater incidence of BER ... like letting your containers or beds go dry and then soaking them down. Even watering is the key. Soaker hoses or drip lines are great if you can afford them. I use heavily organic soil topped with heavy mulch because I'm cheap.
Be very careful not to roto-till, hoe or otherwise cultivate the soil within the major root zone of a tomato plant. Root pruning during fruit development will cause BER. Again, mulch heavy and maybe lay down walking path boards to protect against soil compaction or root damage especially when your rows are close together and the root zone extends into the space between the plant rows.
If you still end up experimenting with or applying a calcium solution directly to the plants ... whether foliar sprays, topical applications to the fruit, or root drenches ... try a calcium solution at the rate of 4 tablespoons (level, not heaping) calcium chloride or calcium nitrate per one gallon of water.
Always be careful with calcium chloride because at daytime temperatures above 85* F, calcium chloride can burn tomato plants. If you have to spray calcium during high temp. conditions, calcium nitrate is a better choice.
Problem, again, with spraying calcium, you need to spray two or three times a week beginning when the second flower blossoms begin blooming, assuming you're getting fruit set, to do any good delivering the calcium to its target destination inside the developing young fruit walls. And such frequent applications, especially if they are root drenches, may risk altering soil pH. But you can test for that at the end of the season and, if needed, add sulfur to rebalance your soil toward acidity.
Remember, spraying calcium will not substitute for proper cultural practices such as cultivar selection, soil building with organic material, soil fertility management, soil pH management, mulching, and proper irrigation.
Also remember, if you get BER, immediately remove and discard the damaged fruit because the rot will continue to degrade the tomato and provide bacteria and fungi a route into the plant.
Good growing in 2010!!!
Bill